We intend to concentrate our efforts on linkage and selection theory extending the work of (2), (5) and (9), the theory of cultural and polygenic transmission as in (11) and (14), the nature of population structure and selection migration interaction following the lines of (3) and (4). On linkage and selection the main effort will be directed toward developing a useful classification of selection regimes, levels and forms of epistasis, relevant parameterizations of the recombination process and the introduction of suitable descriptive procedures for the evaluation of gamete frequency configuration data with objective to the interpretation and meaningful association among these components. The concepts of comparing multilocus sets of recombination frequencies (What is "more recombination"?) is under development. A number of classifications of selection regimes including mixtures of multiplicative and additive nonepistatic viability effects across sets of loci and forms and generalized symmetric heterotic selection expression are under intensive investigation. A general theory of genes which modify evolutionarily important effects on other genes is also under scrutiny. This includes studies with both constant and temporally varying viabilities. The theory of cultural transmission will be extended to included behavior of social importance (e.g., altruism). Also models of assortative mating of discretely and continuously varying phenotypes are to be studied, with and without selection. In a similar vein, mixed epidemic-genetic transmission schemes representing the contagion of certain specific diseases are under analysis. The nature of migration selection interaction will be investigated in the context of multilocus traits also incorporating various forms of non-random mating patterns. The present phase of work on gene map building should be concluded soon and will be followed by studies in which the behavior of many alleles and genes will be considered jointly.